What are the costs of the megadrought in the Southwest?

Here are the basics:

The extreme heat and dry conditions of the past few years pushed what was already an epic, decades-long drought in the American West into a historic disaster that bears the unmistakable fingerprints of climate change. The long-running drought, which has persisted since 2000, can now be considered the driest 22-year period of the past 1,200 years, according to a study published Monday in the journal Nature Climate Change.

Previous work by some of the same authors of the new study had identified the period of 2000 through 2018 as the second-worst megadrought since the year 800 — exceeded only by an especially severe and prolonged drought in the 1500s. But with the past three scorching years added to the picture, the Southwest’s megadrought stands out in the record as the “worst” or driest in more than a millennium.

Here is the WaPo story. I now have three questions, none meant sarcastically, I really want to know:

1. How much has gdp in these regions been damaged over this time period?

2. How much have real estate prices been danaged?

3. How much has migration into these states declined, relative to what would have been the baseline?

Now this is by no means the only set of costs from global warming and climate change. But if we are just trying to calculate the costs of climate change on the Southwest, and other dry but rich areas, which inferences should we draw? You might think “the real problems haven’t come yet,” and maybe so, but shouldn’t that show up in the asset prices and migration patterns?